Amusement park rides that know when you're scared

What would it feel like to ride on a roller-coaster that reacts to your emotional state? Visitors to amusement parks may soon be able to find out.

A team from the University of Nottingham, UK, have used "bio-feedback" to adjust the function of a bucking bronco ride and other amusement-park experiences. They say that ride designers are already expressing an interest in their findings.

Riders who tried the bronco were hooked up to an adapted medical sensor that monitored their breathing. The readings from the monitor were fed back to the bronco controls; as the breathing became less regular, the bronco began to speed up. It made for a tough challenge, as the jerky motion of the bronco is hardly calming. "At some point your breathing speeds up, you lose control and fall off the ride," says Joe Marshall, part of the Nottingham team.

Riders tended to concentrate very hard on the experience, in contrast to the flamboyant yee-haw shouts that riders usually emit, adds Marshall:

Pretty much everyone said it was an odd experience, not like anything they'd experienced before

Marshall's colleague Steve Benford, together with artist and engineer Brendan Walker, is working to together to explore new ways of making rides scary. They used biofeedback to transform the experience a common piece of playground equipment - a swing - into a sinister out-of-control ride. The motions of the swing were driven by a motor that was controlled by the breathing of a person standing nearby. To make the experience unnerving, the person's breathing was monitored by a sensor in an adapted NATO gas mask that they were wearing. The mask was also connected to a loudspeaker, so that the breathing could be heard by everyone present. "The emotional value we're interested in here is fear," says Benford. Riders described the experience as "really disquieting," he adds.

The Nottingham team say they have presented their work to the companies that run Alton Towers and Thorpe Park, two large UK amusement parks. They hope that their work will inspire a new generation of ride designs, but note that there is a historical precedent for what they are doing. Most rides are now totally automated, but fairground operators used to monitor the expressions of customers' faces and adjust the speed of the ride accordingly. "In some ways this is a step backwards," says Marshall.